Electronic Mini Projects
The Wireless Imaging Intruder Alarm application allows home security smartphones to detect and send pictures of burglars directly to personal cell phones, PDAs, or computers within seconds of a break-in at homes or businesses when the owner is away. Code Alarm Security Systems provide burglars with an 8 to 12-minute window to enter and exit a property, leading to potential loss of property and identity information. Law enforcement statistics indicate that less than 12% of burglars are apprehended without instant or preserved photographic evidence of the crime. It is crucial to receive images of intruders on a cell phone to prevent property loss and surprise encounters. Approximately 280,000 U.S. residents (14% of reported home burglaries) are expected to have unexpected encounters with intruders this year, often when returning home from various activities. Immediate awareness of a break-in is essential to mitigate risks such as false alarms, identity theft, and property loss, while also ensuring rapid police response and providing law enforcement with a verified description of the intruder. Home burglaries are a significant source of identity theft and other violent crimes, with statistics suggesting that three out of four U.S. homes may be burglarized within the next 20 years. The Wireless Imaging Intruder Alarm aims to enhance safety by delivering instant images of intruders to cell phones during break-ins.
Most power supply failure indicator circuits require a separate power source; however, the alarm circuit described here operates without one. It utilizes an electrolytic capacitor to store sufficient charge to power the alarm circuit, which activates an alarm for a reasonable duration upon supply failure. This circuit is designed to warn users of potential fire hazards by detecting smoke. When smoke passes between a light bulb and a light-dependent resistor (LDR), the light intensity on the LDR decreases, causing its resistance to increase. This increase in resistance raises the voltage at the base of a transistor, completing the power supply to the chip-on-board (COB) sound generator. Various COBs are available for generating different alarm sounds, and the choice depends on user preference. The sound generated is amplified by an audio amplifier, specifically an IC TDA 2002.
The circuit's sensitivity is adjustable based on the positioning of the bulb and LDR, as well as the setting of a variable resistor (VR1). By optimizing the distances between the components and adjusting VR1, the desired sensitivity can be achieved. The circuit can also incorporate a simple tone generator, utilizing a single 3-terminal IC (UM66) powered by a 3V button cell. The UM66 functions as a miniature tone generator with a built-in ROM containing multiple tunes.
The alarm system activates under four conditions: when light falls on LDR1, when light on LDR2 is obstructed, when door switches are opened or wires are cut, and when a handle is touched. LDR1 is positioned in darkness near the door lock or handle; if an intruder shines a flashlight, the light reduces the voltage across LDR1, triggering the alarm. Sensitivity can be adjusted with preset VR1. LDR2 is placed to detect shadows in a corridor, which increases its voltage drop when an intruder passes through.
A wire may connect points A and B or C and D across windows or doors; if cut, the alarm activates. Alternatively, door switches can be installed to trigger the alarm when doors are opened. A touch point may be connected to the door handle; touching this point activates the alarm. Proper adjustment of potentiometer VR3 is necessary to avoid false triggers.
For alarms requiring higher voltages or currents, a relay circuit is employed. Battery backup is essential for the alarm circuit. The circuit is designed to minimize false triggers from electric sparking.
An FM radio-controlled anti-theft alarm can be integrated into vehicles with a 6- to 12-volt DC supply. A mini VHF FM transmitter is installed in the vehicle, while a receiver module, such as the CXA1019, is kept inside. The receiver is tuned to the transmitter's frequency; when signals are received, the relay remains deactivated. If an intruder attempts to drive the vehicle away, the radio link breaks, generating a hissing noise that activates the alarm. This design ensures reliability even if the transmitter is disconnected.
Additionally, a daylight alarm circuit utilizing a 555 timer IC operates as an astable multivibrator. When no light is detected, the transistor remains off, keeping the 555 timer reset. When light is detected, the transistor turns on, enabling the 555 timer to produce an alarm sound. This circuit can also emulate a police siren using two 555 timer ICs for varied frequencies.
An infrared beam barrier or proximity detector can be constructed using popular IR modules, with the circuit incorporating a 555 timer IC as an oscillator tuned to approximately 38 kHz. The duty cycle of the IR beam is adjustable to optimize performance.Wireless Imaging Intruder Alarm app enables Home Security Smartphones to detect and send burglar pictures direct to your personal cell phone, PDA or computer within a few seconds of a break-in at your home or business when you are away. Code Alarm Security Systems allow a burglar the 8 to 12 minutes needed to get in and out of your home and escape
with your property and identity information. Any law enforcement officer will confirm this fact is accurate on average. Less then 12% of burglars are arrested when you have no instant or preserved photo evidence of the robbery suspect. You need to see pictures of a burglar on your cell phone when a burglary happens to prevent property losses and surprise encounters.
280, 000 US residents (14% of reported home burglaries) will have surprise encounters with burglars inside their homes this year. It happens when returning home from school, work, shopping etc. When a burglar invades your home you need to know immediately and you need to know before a surprise encounter and 1.
Eliminate false alarms. 2. Prevent identity theft and property losses. 3. Preserve photo evidence. 4. Get the fastest police response. 5. Decrease your family`s risk of a surprise encounter with a burglar inside your home. 6. Provide responding police with a verified description of the burglar. Home burglaries are a prime source of identity theft, assaults, robberies, rapes and homicides. "In fact, statistics indicate that three out of four U. S. homes will be burglarized in the next 20 years. " Make your home and family safe with instant direct pictures to your cell phone when a burglar is inside your home. Protect the things you value most. You need to know if harm is waiting before you enter an empty house or apartment. Be smart, be safe, use Wireless Imaging Intruder Alarm to see a burglar if and when your home becomes the target of a break-in when you are away.
Get support, download full version and upgrades to WIIA 1. 66 on our web site. Most of the power supply failure indicator circuits need a separate power supply for themselves. But the alarm circuit presented here needs no additional supply source. It employs an electrolytic capacitor to store adequate charge, to feed power to the alarm circuit which sounds an alarm for a reasonable duration when the supply fails. This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and the voltage at the base of the transistor is pulled high due to which the supply to the COB (chip-on-board) is completed.
Different COBs are available in the market to generate different sounds. The choice of the COB depends on the user. The signal generated by COB is amplified by an audio amplifier. In this circuit, the audio power amplifier is wired around IC TDA 2002. The sensitivity of the circuit depends on the distance between bulb and LDR as well as setting of preset VR1. Thus by placing the bulb and the LDR at appropriate distances, one may vary preset VR1 to get optimum sensitivity.
This tiny circuit comprising of a single 3 terminal IC UM66 can be built small enough to be placed inside a greeting card and operated off a single 3V flat button cell. There is not much to the circuit. The UM66 is connected to its supply and its output fed to a transistor for amplification. You can either use a 4ohm speaker or a " flat" piezoelectric tweeter like the one found in alarm wrist watches.
If you use the piezo, then it can be connected directly between the output pin 1 and ground pin 3 without the transistor. The UM66 looks like a transistor with 3 terminals. It is a complete miniature tone generator with a ROM of 64 notes, oscillator and a preamplifier. When it first came into market, it was programmed for the "Jingle bells" tune. Now they come with a wide variety of different tunes. I n this circuit, the alarm will be switched on under the following four different conditions: 1. When light falls on LDR1 (at the entry to the premises). 2. When light falling on LDR2 is obstructed. 3. When door switches are opened or a wire is broken. 4. When a handle is touched. The light dependent resistor LDR1 should be placed in darkness near the door lock or handle etc. If an intruder flashes his torch, its light will fall on LDR1, reducing the voltage drop across it and so also the voltage applied to trigger 1 (pin 6) of IC1.
Thus transistor T2 will get forward biased and relay RL1 energise and operate the alarm. Sensitivity of LDR1 can be adjusted by varying preset VR1. LDR2 may be placed on one side of a corridor such that the beam of light from a light source always falls on it. When an intruder passes through the corridor, his shadow falls on LDR2. As a result voltage drop across LDR2 increases and pin 8 of IC1 goes low while output pin 9 of IC1 goes high.
Transistor T2 gets switched on and the relay operates to set the alarm. The sensitivity of LDR2 can be adjusted by varying potentiometer VR2. A long but very thin wire may be connected between the points A and B or C and D across a window or a door. This long wire may even be used to lock or tie something. If anyone cuts or breaks this wire, the alarm will be switched on as pin 8 or 6 will go low. In place of the wire between points A and B or C and D door switches can be connected. These switches should be fixed on the door in such a way that when the door is closed the switch gets closed and when the door is open the switch remains open.
If the switches or wire, are not used between these points, the points should be shorted. With the help of a wire, connect the touch point (P) with the handle of a door or some other suitable object made of conducting material. When one touches this handle or the other connected object, pin 6 of IC1 goes low. So the alarm and the relay gets switched on. Remember that the object connected to this touch point should be well insulated from ground. For good touch action, potentiometer VR3 should be properly adjusted. If potentiometer VR3 tapping is held more towards ground, the alarm will get switched on even without touching.
In such a situation, the tapping should be raised. But the tapping point should not be raised too much as the touch action would then vanish. When you vary potentiometer VR1, re-adjust the sensitivity of the touch point with the help of potentiometer VR3 properly. If the alarm has a voltage rating of other than 6V (more than 6V), or if it draws a high current (more than 150 mA), connect it through the relay points as shown by the dotted lines.
As a burglar alarm, battery backup is necessary for this circuit. Note: Electric sparking in the vicinity of this circuit may cause false triggering of the circuit. To avoid this adjust potentiometer VR3 properly This FM radio-controlled anti- theft alarm can be used with any vehicle having 6- to 12-volt DC supply system. The mini VHF, FM transmitter is fitted in the vehicle at night when it is parked in the car porch or car park.
The receiver unit with CXA1019, a single IC-based FM radio module, which is freely available in the market at reasonable rate, is kept inside. Receiver is tuned to the transmitter`s frequency. When the transmitter is on and the signals are being received by FM radio receiver, no hissing noise is available at the output of receiver.
Thus transistor T2 (BC548) does not conduct. This results in the relay driver transistor T3 getting its forward base bias via 10k resistor R5 and the relay gets energised. When an intruder tries to drive the car and takes it a few metres away from the car porch, the radio link between the car (transmitter) and alarm (receiver) is broken.
As a result FM radio module gene-rates hissing noise. Hissing AC signals are coupled to relay switching circ- uit via audio transformer. These AC signals are rectified and filtered by diode D1 and capacitor C8, and the resulting positive DC voltage provides a forward bias to transistor T2. Thus transistor T2 conducts, and it pulls the base of relay driver transistor T3 to ground level. The relay thus gets de-activated and the alarm connected via N/C contacts of relay is switched on. If, by chance, the intruder finds out about the wireless alarm and disconnects the transmitter from battery, still remote alarm remains activated because in the absence of signal, the receiver continues to produce hissing noise at its output.
So the burglar alarm is fool-proof and highly reliable. The circuit presented here wakes you up with a loud alarm at the break of the daylight. Once again the 555 timer is used here. It is working as an astable multivibrator at a frequency of about 1kHz. The circuit`s operation can be explained as follows:When no light falls on the LDR, the transistor is pulled high by the variable resistor. Hence the transistor is OFF and the reset pin of the 555 is pulled low. Due the this the 555 is reset. When light falls on the LDR, its resistance decreases and pulls the base of the transistor low hence turning it ON.
This pulls the reset pin 4 of the 555 high and hence enables the 555 oscillator and a sound is produced by the speaker. This circuit produces a sound similar to a factory siren. It makes use of a 555 timer Ic used as an astable multivibrator of a center frequency of about 300Hz.
The frequency is controlled by the pin 5 of the IC. When the supply is switched ON, the capacitor charges slowly and this alters the voltage at pin 5 of the IC hence the frequenct gradually increases. After the capacitor is fully charged, the frequency no longer increases. Now when the push button siren control switch is held depressed, the capacitor discharges and the siren frequency also decreases.
This circuit produces a sound similar to the police siren. It makes use of two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. The first IC (left) is wired to work around 1Hz. The 47uF capacitor is charged and discharged periodically and the voltage across it gradually increases and decreases periodically. This circuit can be used as an Infrared beam barrier as well as a proximity detector. The circuit uses the very popular Sharp IR module (Vishay module can also be used). The pin nos. shown in the circuit are for the Sharp & VIshay modules. For other modules please refer to their respective datasheets. The receiver consists of a 555 timer IC working as an oscillator at about 38Khz (also works from 36kHz to 40kHz) which has to be adjusted using the 10K preset.
The duty cycle of the IR beam is about 10%. 🔗 External reference
Most power supply failure indicator circuits require a separate power source; however, the alarm circuit described here operates without one. It utilizes an electrolytic capacitor to store sufficient charge to power the alarm circuit, which activates an alarm for a reasonable duration upon supply failure. This circuit is designed to warn users of potential fire hazards by detecting smoke. When smoke passes between a light bulb and a light-dependent resistor (LDR), the light intensity on the LDR decreases, causing its resistance to increase. This increase in resistance raises the voltage at the base of a transistor, completing the power supply to the chip-on-board (COB) sound generator. Various COBs are available for generating different alarm sounds, and the choice depends on user preference. The sound generated is amplified by an audio amplifier, specifically an IC TDA 2002.
The circuit's sensitivity is adjustable based on the positioning of the bulb and LDR, as well as the setting of a variable resistor (VR1). By optimizing the distances between the components and adjusting VR1, the desired sensitivity can be achieved. The circuit can also incorporate a simple tone generator, utilizing a single 3-terminal IC (UM66) powered by a 3V button cell. The UM66 functions as a miniature tone generator with a built-in ROM containing multiple tunes.
The alarm system activates under four conditions: when light falls on LDR1, when light on LDR2 is obstructed, when door switches are opened or wires are cut, and when a handle is touched. LDR1 is positioned in darkness near the door lock or handle; if an intruder shines a flashlight, the light reduces the voltage across LDR1, triggering the alarm. Sensitivity can be adjusted with preset VR1. LDR2 is placed to detect shadows in a corridor, which increases its voltage drop when an intruder passes through.
A wire may connect points A and B or C and D across windows or doors; if cut, the alarm activates. Alternatively, door switches can be installed to trigger the alarm when doors are opened. A touch point may be connected to the door handle; touching this point activates the alarm. Proper adjustment of potentiometer VR3 is necessary to avoid false triggers.
For alarms requiring higher voltages or currents, a relay circuit is employed. Battery backup is essential for the alarm circuit. The circuit is designed to minimize false triggers from electric sparking.
An FM radio-controlled anti-theft alarm can be integrated into vehicles with a 6- to 12-volt DC supply. A mini VHF FM transmitter is installed in the vehicle, while a receiver module, such as the CXA1019, is kept inside. The receiver is tuned to the transmitter's frequency; when signals are received, the relay remains deactivated. If an intruder attempts to drive the vehicle away, the radio link breaks, generating a hissing noise that activates the alarm. This design ensures reliability even if the transmitter is disconnected.
Additionally, a daylight alarm circuit utilizing a 555 timer IC operates as an astable multivibrator. When no light is detected, the transistor remains off, keeping the 555 timer reset. When light is detected, the transistor turns on, enabling the 555 timer to produce an alarm sound. This circuit can also emulate a police siren using two 555 timer ICs for varied frequencies.
An infrared beam barrier or proximity detector can be constructed using popular IR modules, with the circuit incorporating a 555 timer IC as an oscillator tuned to approximately 38 kHz. The duty cycle of the IR beam is adjustable to optimize performance.Wireless Imaging Intruder Alarm app enables Home Security Smartphones to detect and send burglar pictures direct to your personal cell phone, PDA or computer within a few seconds of a break-in at your home or business when you are away. Code Alarm Security Systems allow a burglar the 8 to 12 minutes needed to get in and out of your home and escape
with your property and identity information. Any law enforcement officer will confirm this fact is accurate on average. Less then 12% of burglars are arrested when you have no instant or preserved photo evidence of the robbery suspect. You need to see pictures of a burglar on your cell phone when a burglary happens to prevent property losses and surprise encounters.
280, 000 US residents (14% of reported home burglaries) will have surprise encounters with burglars inside their homes this year. It happens when returning home from school, work, shopping etc. When a burglar invades your home you need to know immediately and you need to know before a surprise encounter and 1.
Eliminate false alarms. 2. Prevent identity theft and property losses. 3. Preserve photo evidence. 4. Get the fastest police response. 5. Decrease your family`s risk of a surprise encounter with a burglar inside your home. 6. Provide responding police with a verified description of the burglar. Home burglaries are a prime source of identity theft, assaults, robberies, rapes and homicides. "In fact, statistics indicate that three out of four U. S. homes will be burglarized in the next 20 years. " Make your home and family safe with instant direct pictures to your cell phone when a burglar is inside your home. Protect the things you value most. You need to know if harm is waiting before you enter an empty house or apartment. Be smart, be safe, use Wireless Imaging Intruder Alarm to see a burglar if and when your home becomes the target of a break-in when you are away.
Get support, download full version and upgrades to WIIA 1. 66 on our web site. Most of the power supply failure indicator circuits need a separate power supply for themselves. But the alarm circuit presented here needs no additional supply source. It employs an electrolytic capacitor to store adequate charge, to feed power to the alarm circuit which sounds an alarm for a reasonable duration when the supply fails. This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and the voltage at the base of the transistor is pulled high due to which the supply to the COB (chip-on-board) is completed.
Different COBs are available in the market to generate different sounds. The choice of the COB depends on the user. The signal generated by COB is amplified by an audio amplifier. In this circuit, the audio power amplifier is wired around IC TDA 2002. The sensitivity of the circuit depends on the distance between bulb and LDR as well as setting of preset VR1. Thus by placing the bulb and the LDR at appropriate distances, one may vary preset VR1 to get optimum sensitivity.
This tiny circuit comprising of a single 3 terminal IC UM66 can be built small enough to be placed inside a greeting card and operated off a single 3V flat button cell. There is not much to the circuit. The UM66 is connected to its supply and its output fed to a transistor for amplification. You can either use a 4ohm speaker or a " flat" piezoelectric tweeter like the one found in alarm wrist watches.
If you use the piezo, then it can be connected directly between the output pin 1 and ground pin 3 without the transistor. The UM66 looks like a transistor with 3 terminals. It is a complete miniature tone generator with a ROM of 64 notes, oscillator and a preamplifier. When it first came into market, it was programmed for the "Jingle bells" tune. Now they come with a wide variety of different tunes. I n this circuit, the alarm will be switched on under the following four different conditions: 1. When light falls on LDR1 (at the entry to the premises). 2. When light falling on LDR2 is obstructed. 3. When door switches are opened or a wire is broken. 4. When a handle is touched. The light dependent resistor LDR1 should be placed in darkness near the door lock or handle etc. If an intruder flashes his torch, its light will fall on LDR1, reducing the voltage drop across it and so also the voltage applied to trigger 1 (pin 6) of IC1.
Thus transistor T2 will get forward biased and relay RL1 energise and operate the alarm. Sensitivity of LDR1 can be adjusted by varying preset VR1. LDR2 may be placed on one side of a corridor such that the beam of light from a light source always falls on it. When an intruder passes through the corridor, his shadow falls on LDR2. As a result voltage drop across LDR2 increases and pin 8 of IC1 goes low while output pin 9 of IC1 goes high.
Transistor T2 gets switched on and the relay operates to set the alarm. The sensitivity of LDR2 can be adjusted by varying potentiometer VR2. A long but very thin wire may be connected between the points A and B or C and D across a window or a door. This long wire may even be used to lock or tie something. If anyone cuts or breaks this wire, the alarm will be switched on as pin 8 or 6 will go low. In place of the wire between points A and B or C and D door switches can be connected. These switches should be fixed on the door in such a way that when the door is closed the switch gets closed and when the door is open the switch remains open.
If the switches or wire, are not used between these points, the points should be shorted. With the help of a wire, connect the touch point (P) with the handle of a door or some other suitable object made of conducting material. When one touches this handle or the other connected object, pin 6 of IC1 goes low. So the alarm and the relay gets switched on. Remember that the object connected to this touch point should be well insulated from ground. For good touch action, potentiometer VR3 should be properly adjusted. If potentiometer VR3 tapping is held more towards ground, the alarm will get switched on even without touching.
In such a situation, the tapping should be raised. But the tapping point should not be raised too much as the touch action would then vanish. When you vary potentiometer VR1, re-adjust the sensitivity of the touch point with the help of potentiometer VR3 properly. If the alarm has a voltage rating of other than 6V (more than 6V), or if it draws a high current (more than 150 mA), connect it through the relay points as shown by the dotted lines.
As a burglar alarm, battery backup is necessary for this circuit. Note: Electric sparking in the vicinity of this circuit may cause false triggering of the circuit. To avoid this adjust potentiometer VR3 properly This FM radio-controlled anti- theft alarm can be used with any vehicle having 6- to 12-volt DC supply system. The mini VHF, FM transmitter is fitted in the vehicle at night when it is parked in the car porch or car park.
The receiver unit with CXA1019, a single IC-based FM radio module, which is freely available in the market at reasonable rate, is kept inside. Receiver is tuned to the transmitter`s frequency. When the transmitter is on and the signals are being received by FM radio receiver, no hissing noise is available at the output of receiver.
Thus transistor T2 (BC548) does not conduct. This results in the relay driver transistor T3 getting its forward base bias via 10k resistor R5 and the relay gets energised. When an intruder tries to drive the car and takes it a few metres away from the car porch, the radio link between the car (transmitter) and alarm (receiver) is broken.
As a result FM radio module gene-rates hissing noise. Hissing AC signals are coupled to relay switching circ- uit via audio transformer. These AC signals are rectified and filtered by diode D1 and capacitor C8, and the resulting positive DC voltage provides a forward bias to transistor T2. Thus transistor T2 conducts, and it pulls the base of relay driver transistor T3 to ground level. The relay thus gets de-activated and the alarm connected via N/C contacts of relay is switched on. If, by chance, the intruder finds out about the wireless alarm and disconnects the transmitter from battery, still remote alarm remains activated because in the absence of signal, the receiver continues to produce hissing noise at its output.
So the burglar alarm is fool-proof and highly reliable. The circuit presented here wakes you up with a loud alarm at the break of the daylight. Once again the 555 timer is used here. It is working as an astable multivibrator at a frequency of about 1kHz. The circuit`s operation can be explained as follows:When no light falls on the LDR, the transistor is pulled high by the variable resistor. Hence the transistor is OFF and the reset pin of the 555 is pulled low. Due the this the 555 is reset. When light falls on the LDR, its resistance decreases and pulls the base of the transistor low hence turning it ON.
This pulls the reset pin 4 of the 555 high and hence enables the 555 oscillator and a sound is produced by the speaker. This circuit produces a sound similar to a factory siren. It makes use of a 555 timer Ic used as an astable multivibrator of a center frequency of about 300Hz.
The frequency is controlled by the pin 5 of the IC. When the supply is switched ON, the capacitor charges slowly and this alters the voltage at pin 5 of the IC hence the frequenct gradually increases. After the capacitor is fully charged, the frequency no longer increases. Now when the push button siren control switch is held depressed, the capacitor discharges and the siren frequency also decreases.
This circuit produces a sound similar to the police siren. It makes use of two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. The first IC (left) is wired to work around 1Hz. The 47uF capacitor is charged and discharged periodically and the voltage across it gradually increases and decreases periodically. This circuit can be used as an Infrared beam barrier as well as a proximity detector. The circuit uses the very popular Sharp IR module (Vishay module can also be used). The pin nos. shown in the circuit are for the Sharp & VIshay modules. For other modules please refer to their respective datasheets. The receiver consists of a 555 timer IC working as an oscillator at about 38Khz (also works from 36kHz to 40kHz) which has to be adjusted using the 10K preset.
The duty cycle of the IR beam is about 10%. 🔗 External reference
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